Method and apparatus for treating a carotid artery

ABSTRACT

One disclosed embodiment comprises a method for treating lesions in the carotid artery of a mammalian body. The method comprises transcervical access and blocking of blood flow through the common carotid artery (with or without blocking of blood flow through the external carotid artery), shunting blood from the internal carotid artery and treating the lesion in the carotid artery.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/966,974, titled “Method And Apparatus For Treating A CarotidArtery,” filed Dec. 13, 2010, which in turn is a continuation of U.S.patent application Ser. No. 10/996,301, titled “Method And Apparatus ForTreating A Carotid Artery,” filed Nov. 22, 2004, no U.S. Pat. No.7,998,104, which claims the benefit under 35 U.S.C. §119(e) of thefollowing U.S. Provisional Applications: (1) U.S. Provisional PatentApplication Ser. No. 60/524,069, filed Nov. 21, 2003, titled “Method AndApparatus For Carotid Angioplasty And Stenting Using TranscervicalOcclusion And Protective Shunting;” (2) U.S. Provisional PatentApplication Ser. No. 60/569,843, filed May 10, 2004, titled “Method AndApparatus For Carotid Angioplasty And Stenting Using TranscervicalOcclusion And Protective Shunting;” and (3) U.S. Provisional PatentApplication Ser. No. 60/587,067, filed Jul. 12, 2004, titled “Method AndApparatus For Carotid Angioplasty And Stenting Using TranscervicalOcclusion And Protective Shunting.” Priority of the aforementionedfiling dates is hereby claimed, and the disclosures of the Applicationsare hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

Certain inventions disclosed herein relate to treating a carotid artery.For example, a carotid artery may have a lesion or a partial occlusionthat can be treated using the methods and apparatus disclosed herein.

Description of the Related Art

Carotid angioplasty and stenting (CAS) is a minimally invasive approachfor treating carotid stenoses. Since its introduction two decades ago,the use of CAS has steadily increased, with 8% of the 107,000 carotidprocedures performed in Europe in 2001 utilizing CAS. The prospect of anoutpatient procedure without the discomfort of a sizable neck incisionappears to be driving patient decision making away from carotidendarterectomy, the standard procedure for carotid bifurcation diseasefor the past fifty years.

SUMMARY OF THE INVENTION

One disclosed embodiment comprises an apparatus for use in carotidangioplasty. The apparatus comprises a catheter having a distal end anda proximal end opposite the distal end, and first and second occlusivemembers, of which at least the first occlusive member is located on thecatheter. The first and second occlusive members are configured toreverse the natural direction of blood flow in the internal carotidartery when the first occlusive member occludes the common carotidartery and the second occlusive member occludes the external carotidartery. The catheter has a first shaft portion extending proximally fromthe first occlusive member. The first shaft portion has a maximumcross-section sized to be insertable into the common carotid artery. Thefirst shaft portion has a relatively short length suitable fortranscervical access to the common carotid artery. The catheter has ablood entry port located distal of the first occlusive member. Theapparatus further comprises a collection reservoir configured to beconnected to the catheter and placed in passive fluid communication withthe blood entry port.

Another disclosed embodiment comprises a method of treating a lesion ina carotid artery in a patient. The method comprises inserting a catheterinto the carotid vasculature via a transcervical approach, and occludingblood flow in the common carotid artery and the external carotid artery,thus reversing the direction of natural blood flow in the internalcarotid artery. The method further comprises allowing blood to flow intoa blood entry port in the catheter, and passively collecting the bloodin a reservoir.

Another disclosed embodiment comprises an apparatus for use in carotidangioplasty. The apparatus comprises a catheter having a distal end anda proximal end opposite the distal end, and first and second occlusivemembers, of which at least the first occlusive member is located on thecatheter. The first and second occlusive members are configured toreverse the natural direction of blood flow in the internal carotidartery when the first occlusive member occludes the common carotidartery and the second occlusive member occludes the external carotidartery. The catheter has a first shaft portion extending proximally fromthe first occlusive member. The first shaft portion has a maximumcross-section sized to be insertable into the common carotid artery. Thefirst shaft portion has a relatively short length suitable fortranscervical access to the common carotid artery. The catheter has ablood entry port located distal of the first occlusive member. Theapparatus further comprises a passive fluid conduit and a collectionreservoir. The collection reservoir is configured to be connected to thecatheter via the passive fluid conduit.

Another disclosed embodiment comprises a method for treating lesions inthe carotid artery of a mammalian body. The method comprisestranscervical access and blocking of blood flow through the commoncarotid artery, shunting blood from the internal carotid artery to thevenous system of the mammalian body and treating the lesion in thecarotid artery. The method may optionally further comprise blockingblood flow through the external carotid artery.

In the method, access to the carotid artery can optionally be obtainedpercutaneously, or via a cutdown incision, or with any suitabletechnique. The treating step of the method can optionally includedilating the lesion with a balloon. The treating step of the method canoptionally include stenting the dilated lesion. The shunting step of themethod can optionally include filtering the blood for debris. Theblocking step of the method can optionally include occluding theexternal carotid artery with a balloon. The blocking step of the methodcan optionally include occluding the common carotid artery with aballoon. The blocking step of the method can optionally include clampingthe common carotid artery. The introducing step of the method canoptionally include positioning a single sheath with balloons to occludethe common and external carotid artery and a side port for deployment ofan angioplasty balloon or stent. The blocking step of the method canoptionally include introducing at least one catheter directly into thecommon carotid artery. The introducing step of the method can optionallyinclude introducing first and second introducer sheaths directly intothe common carotid artery. The introducing step of the method canoptionally include introducing first and second balloon cathetersdirectly into the common carotid artery.

Another disclosed embodiment comprises a method for treating lesions inthe carotid artery. The method comprises transcervical access, blockingblood flow through the common carotid artery to allow safe treatment ofthe lesion and returning blood flow back to the carotid artery. Themethod may further comprise blocking blood flow through the externalcarotid artery.

In the method, the blood in the carotid artery may be actively withdrawnand returned to the carotid artery. In the method, access to the carotidartery can optionally be obtained percutaneously, or via a cutdownincision, or with any suitable technique. The treating step of themethod can optionally include dilating the lesion with a balloon. Thetreating step of the method can optionally include stenting the dilatedlesion. The shunting step of the method can optionally include filteringthe blood for debris. The blocking step of the method can optionallyinclude occluding the external carotid artery with a balloon. Theblocking step of the method can optionally include occluding the commoncarotid artery with a balloon. The blocking step of the method canoptionally include clamping the common carotid artery. The introducingstep of the method can optionally include positioning a single sheathwith balloons to occlude the common and external carotid artery and aside port for deployment of an angioplasty balloon or stent. Theblocking step of the method can optionally include introducing at leastone catheter directly into the common carotid artery. The introducingstep of the method can optionally include introducing first and secondintroducer sheaths directly into the common carotid artery. Theintroducing step of the method can optionally include introducing firstand second balloon catheters directly into the common carotid artery.

Another disclosed embodiment comprises a method for treatment of lesionsin the carotid artery. The method comprises transcervical access,blocking blood flow through the common carotid artery and passivecollection of blood and debris and subsequent return of filtered bloodto the carotid artery. The method may further comprise blocking bloodflow through the external carotid artery.

In the method, access to the carotid artery can optionally be obtainedpercutaneously, or via a cutdown incision, or with any suitabletechnique. The treating step of the method can optionally includedilating the lesion with a balloon. The treating step of the method canoptionally include stenting the dilated lesion. The shunting step of themethod can optionally include filtering the blood for debris. Theblocking step of the method can optionally include occluding theexternal carotid artery with a balloon. The blocking step of the methodcan optionally include occluding the common carotid artery with aballoon. The blocking step of the method can optionally include clampingthe common carotid artery. The introducing step of the method canoptionally include positioning a single sheath with balloons to occludethe common and external carotid artery and a side port for deployment ofan angioplasty balloon or stent. The blocking step of the method canoptionally include introducing at least one catheter directly into thecommon carotid artery. The introducing step of the method can optionallyinclude introducing first and second introducer sheaths directly intothe common carotid artery. The introducing step of the method canoptionally include introducing first and second balloon cathetersdirectly into the common carotid artery.

Certain objects and advantages of the invention are described herein. Ofcourse, it is to be understood that not necessarily all such objects oradvantages may be achieved in accordance with any particular embodimentof the invention. Thus, for example, those skilled in the art willrecognize that the invention may be embodied or carried out in a mannerthat achieves or optimizes one advantage or group of advantages astaught herein without necessarily achieving other objects or advantagesas may be taught or suggested herein.

All of the embodiments summarized above are intended to be within thescope of the invention herein disclosed. However, despite the foregoingdiscussion of certain embodiments, only the appended claims (and not thepresent summary) are intended to define the invention. The summarizedembodiments, and other embodiments of the present invention, will becomereadily apparent to those skilled in the art from the following detaileddescription of the preferred embodiments having reference to theattached figures, the invention not being limited to any particularembodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one embodiment of a method and apparatusfor treating a carotid artery.

FIG. 2 is a schematic view of another embodiment of a method andapparatus for treating a carotid artery.

FIG. 2A is a side view of a dilator tip usable with apparatus andmethods disclosed herein, including the apparatus and methods of FIG. 2.

FIG. 3 is a schematic view of another embodiment of a method andapparatus for treating a carotid artery.

FIG. 3A is a side view of a blocker and pusher rod usable with apparatusand methods disclosed herein, including the apparatus and methods ofFIG. 3.

FIG. 3B is a detail view of another embodiment of the catheter shown inFIG. 3.

FIG. 4 is a schematic view of another embodiment of a method andapparatus for treating a carotid artery.

FIG. 4A a schematic view of another embodiment of the pump reservoirshown in FIG. 4.

FIG. 5 is a schematic view of another embodiment of the pump reservoirof FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An approach called Transcervical Occlusion (of the CCA) and ProximalShunting (TOPS) can be employed in carotid angioplasty.

In one embodiment, depicted in FIG. 1, a method of treating a carotidartery can be performed in the operating theater. After mild sedation ofthe patient, a mixture of 1% lidocaine and 0.5% marcaine can be used toanesthetize the skin two centimeters above the clavicle. A 2 cmtransverse incision is made centered over the medial border of thesternocleidomastoid muscle. The muscle is retracted laterally and thecommon carotid artery (CCA) 12 exposed circumferentially over atwo-centimeter length.

After heparin (for example, about 70 IU/kg to about 100 IU/kg) isadministered to increase the activated clotting time (to greater than250 seconds, for example), a needle (not shown) is introduced directlyinto the CCA 12 above the position of a surgical clamp 14. Injection ofcontrast under fluoroscopy in the appropriate anterior oblique planelocalizes the carotid bifurcation and the lesion 16 in a “worst view”magnified angiogram. A guidewire (not shown) is advanced to the distalcarotid bulb 22 or to the external carotid artery 20. A first sheath 24is advanced until the dilator (a component of the sheath not shown)straightens the tip of the guidewire and then the sheath 24 is advancedover the dilator to the distal CCA 13 or the external carotid artery(ECA) 20. Intracranial carotid angiography is performed (AP Towne andlateral view) to document any pre-existent intracranial arterialpathology and to evaluate collateral circulation.

The first sheath 24 can be placed directly in the CCA 12 parallel to asmaller second introducer sheath 26 placed with its tip in the distalCCA 13. A stitch may be placed around the entrance of the first sheath24 and a vascular tourniquet (not shown) and umbilical tape (not shown)may be looped around the CCA to allow rapid hemostasis of the puncturesite in the event of catheter dislodgement. A guidewire is directed intothe ECA 20 through the first arterial sheath 24 and a balloon catheter25 is used to occlude the proximal ECA 21. Occlusion of the ECA 20 andreversal of blood flow in the internal carotid artery (ICA) 42 can beverified with angiography after clamping the CCA 12.

A sidearm 30 of the first sheath 24 is connected to a filter 34 with aholder apparatus (not shown) that is attached to a sidearm 38 of a thirdsheath 28 in fluid communication with the internal jugular vein 40. Thisconfiguration forms a shunt 32. With the surgical clamp 14 applied tothe CCA 12, retrograde flow of contrast from the internal carotid artery(ICA) 42 into the internal jugular vein 40 through the shunt 32 can beconfirmed using fluoroscopy or duplex ultrasound. The carotid lesion 16is crossed with a guidewire 27 from the second sheath 26 under flowreversal cerebral protection and the lesion 16 is dilated with a balloon29.

If rapid retrograde flow of contrast is not seen with initiation of theshunt 32, forceful aspiration of blood using a syringe (for example a 20cc syringe) through the first sheath 24 is performed, for example, aftereach angioplasty. Hence, retrograde passage of embolic material isprovided. The blood is returned to the patient through a three waystopcock (for example, stopcock 44 and stopcock 46) attached to theshunt 32 or filter 34. A stent (for example an 8 or 10 mm×24 mm stent)can be deployed across the lesion 16 into the CCA 12. The stent can beserially post dilated with an angioplasty balloon (for example a 5 or 6mm×2 cm angioplasty balloon).

Completion of cervical and intracranial carotid angiography is performedafter releasing the external carotid occlusion balloon 25 and the commoncarotid clamp 14. Once satisfactory treatment of the lesion 16 isobserved, the first arterial sheath 24 and second arterial sheath 26 areremoved with simultaneous repair of the arterial punctures usingpreviously placed exit site sutures.

In some embodiments, either or both of the sheaths 24, 26 may have aninsertable length or first shaft portion extending proximally from thedistal end of the sheath(s). Over the entirety of the insertable length,the sheath(s) 24, 26 have a cross-sectional size (e.g., about 6-8French) which is suitable for insertion into the CCA 12. (Although thecross-sectional size need not be uniform along the insertable length,the maximum cross-sectional size along the insertable length should besuitable for insertion into the CCA.) In certain such embodiments, theinsertable length is less than about 75 cm, less than about 50 cm, lessthan about 30 cm, or less than about 15 cm. In still other embodiments,the insertable length is between about 2 cm and about 25 cm, or betweenabout 2 cm and about 15 cm. More generally, the insertable length may berelatively short as may be suitable for transcervical access to the CCA.

In some embodiments, one or both of the shafts 24 a, 26 a of the sheaths24, 26 is constructed to be generally rigid. Advantageously, a rigidsheath 24/26 can be inserted into the CCA 12 without need to “ride” thesheath 24/26 over a guidewire. As another alternative either shaft 24a/26 a may be made generally rigid but sufficiently malleable to permitthe user to “pre-bend” the shaft 24 a/26 a, such that the shaftmaintains the bent shape imparted by the user. With such a malleableshaft 24 a/26 a, the user can custom-shape the sheath 24/26 to fit thevasculature of the patient, and more easily manipulate the sheath 24/26into position in the CCA 12. The pre-bend may be made based on theuser's observations of the patient's carotid vasculature. A sheath 24/26which is rigid and/or malleable as discussed above can be made fromstainless steel or suitable soft metals, or any suitable polymericmaterials.

In another embodiment, illustrated in FIGS. 2 and 2A, a device 210 withonly one arterial sheath or catheter 224 is used. A dilator 250 (seeFIG. 2A) for the arterial sheath 224 may have a shorter taper thanconventional arterial sheaths and may be angled or curved towards thetip to help prevent injury to or dissection of the back wall of theartery. The stent/ICA angioplasty balloon 229 and the ECA occlusionballoon 225 are passed through the single sheath 224, which ispreferably large enough to deploy both balloons 225, 229 as well asprovide a lumen of sufficient size to facilitate retrograde passage ofembolic material through the sheath 224. This sheath may have a balloon252 that prevents the sheath from dislodging and also may be largeenough to occlude the CCA 212, effectively replacing the surgical clamp14 of the embodiment of FIG. 1. The lesion 216 in the ICA 242 may becrossed with a guidewire and dilated with the stent/ICA angioplastyballoon 229. The sidearm 230 of the arterial sheath 224 may have anopening 256, which is preferably larger than the opening of a typicalsheath, thus preventing a bottleneck for flow of blood carrying largeembolic debris. A flow sensor 258 (a Doppler sensor, for example) may bepart of the flow circuit, allowing for real-time and failsafeverification of flow and direction. A contrast injection/bloodaspiration apparatus 260 can be attached to the sidearm 230 near thesideport 256, along with a contrast reservoir 264, to preventinadvertent air embolism. A stopcock 244 can be employed at the junctionbetween the sidearm 230 and injection/aspiration apparatus 260. Whenstopcock 244 is open, the opened passage preferably has a large lumen. Afilter 268 can also be attached to the sidearm 230. The filter apparatusmay be made integral to the device 210 to simplify the components in thedevice 210. As indicated by flow arrow 272, sidearm 230 can lead to avenous sheath (not shown) such as the sheath 28 of the embodiment ofFIG. 1.

In some embodiments, the sheath 224 may have an insertable length orfirst shaft portion extending proximally from the balloon 252. Over theentirety of the insertable length, the sheath 224 has a cross-sectionalsize (e.g., about 6-8 French) which is suitable for insertion into theCCA 12. (Although the cross-sectional size need not be uniform along theinsertable length, the maximum cross-sectional size along the insertablelength should be suitable for insertion into the CCA.) In certain suchembodiments, the insertable length is less than about 75 cm, less thanabout 50 cm, less than about 30 cm, or less than about 15 cm. In stillother embodiments, the insertable length is between about 2 cm and about25 cm, or between about 2 cm and about 15 cm. More generally, theinsertable length may be relatively short as may be suitable fortranscervical access to the CCA.

In some embodiments, the shaft 224 a of the sheath 224 is constructed tobe generally rigid. Advantageously, a rigid sheath 224 can be insertedinto the CCA 12 without need to “ride” the sheath 224 over a guidewire.As another alternative the shaft 224 a may be made generally rigid butsufficiently malleable to permit the user to “pre-bend” the shaft 224 a,such that the shaft maintains the bent shape imparted by the user. Withsuch a malleable shaft 224 a, the user can custom-shape the sheath 224to fit the vasculature of the patient, and more easily manipulate thesheath 224 into position in the CCA 12. The pre-bend may be made basedon the user's observations of the patient's carotid vasculature. Asheath 224 which is rigid and/or malleable as discussed above can bemade from stainless steel or suitable soft metals, or any suitablepolymeric materials.

In a further embodiment, illustrated in FIGS. 3, 3A and 3B, the arterialcatheter/sheath 324 of the apparatus has an opening 374 in the side ofthe sheath distal of a first inflatable membrane or balloon 352, locatedon the outside of the sheath 324. A second inflatable membrane orballoon 325 is located on the outside of the sheath 324, distal of theopening 374. The balloon sheath 324 is inserted into the ECA 320, forexample over a guidewire (not shown). After the guidewire (not shown)has been removed from the sheath 324, a blocker 378 (also shown in FIG.3A) is passed through the sheath 324 to occlude the distal lumen 373 ofthe sheath 324. The blocker 378 can be delivered by means of adetachable pusher rod 380. Alternately, a valve (not shown) or othermechanism may be fashioned to close the lumen 373 of the sheath 324leading to ECA 320 after removal of the guidewire. The second balloon325 is then inflated to create a seal preventing flow in the ECA 320.The first balloon 352 may be inflated to occlude the CCA 312. Anangioplasty balloon and stent 329 may then be passed over a guidewire376 through the side opening 374 in the arterial sheath 324, and intothe internal carotid artery 342, with or without predilation angioplastyof the lesion 316.

In one embodiment, the first balloon 352 has an inflated diameter of upto about 13 mm and the second balloon 325 has an inflated diameter of upto 6 mm. The balloons are preferably spaced about 2-6 cm apart on thesheath 324.

A sliding or removable sleeve 382 (see FIG. 3B) may be included to coverthe side opening 374 in the arterial sheath 324, allowing two catheters(not shown) to pass through the sheath 324 without blood leakage out ofthe sheath 324 into the operative field external of the patient. Theflexible and removable sleeve 382 may be formed from any suitablematerial such as plastic or be formed from any suitable peelable tape.

A sheath equipped with the sleeve 382 may be useful, for example, fortreating common carotid lesions (not shown) or treating internal carotidlesions when the ECA is occluded. In these cases, the sheath cannot beextended into the occluded ECA so only the very tip of the sheath 324with the distal second balloon 325 is placed into and occludes the CCA352. There is no need for a separate ECA occlusion balloon if the ECA isalready occluded or severely narrowed with disease. Such a positioningof the sheath may result in the side opening 374 or hole in the sheathbeing external the patient. The side opening 374 is thus covered withthe sleeve 382 to inhibit or prevent blood from spurting out of thesheath 324 onto the operative field.

An occluded ECA is not shown in FIG. 3, but the following descriptionassumes an occluded ECA, and the second balloon 325 positioned in, andoccluding, the CCA 312. A catheter (e.g. the catheter 329) forperforming angioplasty and stent deployment is passed through the end ofthe sheath for positioning in the ICA 342. In this manner, the sheath324 of FIG. 3 operates in a manner similar to the sheath 224 of FIG. 2,with the second balloon 325 serving to occlude the CCA 312. The firstuninflated balloon 352 of the sheath 324 remains outside of the patientand thus inactive. Note, in this case, no blocker 378 is used.

If the ECA is not occluded, the sleeve 382 can be either peeled away orslid away to allow the sheath 324 to be pushed farther distally throughthe incision and into the hole in the artery so that the second balloon325 is positioned in the ECA 320. Such a placement of the sheath 324, asdiscussed above, permits deployment of the stent 329 through thesidehole 374 instead of through the end hole 373 of the sheath 324. Thedecision concerning where to place the tip of the sheath is made duringthe initial angiogram. As can be appreciated, such a sheath may also beuseful for performing the procedure illustrated in FIG. 2.

As indicated by flow arrow 372, a sidearm 330 of the sheath 324 can leadto a shunt such as the shunt 32 described above, a filter, a contrastinjection/blood aspiration apparatus such as the apparatus 260 describedabove, a contrast reservoir such as the reservoir 264 described above,stopcocks, a venous sheath such as the sheath 28 of FIG. 1, or anycombination of the above.

In an alternative embodiment, the sheath 324 of FIGS. 3-4 may have aclosed distal tip (instead of the open tip and blocker shown in FIGS.3-4). Such a closed distal tip preferably has a tapered, atraumaticconfiguration. With a closed distal tip, the sheath 324 can be insertedinto the CCA 12 and ECA 320 without the use of a guidewire.

In some embodiments, the sheath 324 may have an insertable length orfirst shaft portion extending proximally from the first balloon 352.Over the entirety of the insertable length, the sheath 324 has across-sectional size (e.g., about 6-8 French) which is suitable forinsertion into the CCA 12. (Although the cross-sectional size need notbe uniform along the insertable length, the maximum cross-sectional sizealong the insertable length should be suitable for insertion into theCCA.) In certain such embodiments, the insertable length is less thanabout 75 cm, less than about 50 cm, less than about 30 cm, or less thanabout 15 cm. In still other embodiments, the insertable length isbetween about 2 cm and about 25 cm, or between about 2 cm and about 15cm. More generally, the insertable length may be relatively short as maybe suitable for transcervical access to the CCA.

In some embodiments, the shaft 324 a of the sheath 324 is constructed tobe generally rigid. Advantageously, a rigid sheath 324 can be insertedinto the CCA 12 without need to “ride” the sheath 324 over a guidewire.As another alternative the shaft 324 a may be made generally rigid butsufficiently malleable to permit the user to “pre-bend” the shaft 324 a,such that the shaft maintains the bent shape imparted by the user. Withsuch a malleable shaft 324 a, the user can custom-shape the sheath 324to fit the vasculature of the patient, and more easily manipulate thesheath 324 into position in the CCA 12. The pre-bend may be made basedon the user's observations of the patient's carotid vasculature. Asheath 324 which is rigid and/or malleable as discussed above can bemade from stainless steel or suitable soft metals, or any suitablepolymeric materials.

Certain embodiments do not employ venous shunting. One such embodimentis illustrated in FIG. 4. The arterial sheath sidearm 330 is in fluidcommunication with a pump 484 that allows control and verification ofthe amount of flow. After passing through a filter (that can be includedwith pump 484), the blood is returned to the arterial sheath 324. Bloodreturn may be accomplished through a separate arterial channel 486 or bycausing the blood to flow into a pump reservoir 488 (see FIG. 4A) andreturning the blood through the same sidearm port 330 a after the periodof cerebral protection. The latter approach may employ valves such asvalves 490 and 491.

FIG. 5 illustrates an embodiment of a reservoir apparatus 588 that maybe employed to passively collect blood from the sidearm 30/230/330 ofthe sheath 24/224/324. The apparatus 588 comprises a filter 568, valves590, 591 and 597, blood inlet port 592, blood outlet port 593, plunger594, reservoir 598, and air outlet port 596. The sidearm 30/230/330 isconnected to the blood inlet port 592 and the valve 591 is initially setto permit blood flowing from the sidearm to flow from the inlet port 592into the reservoir 598, while the valve 590 is initially set to preventfluid from flowing from the reservoir 598 past the valve 590. Inaddition, the blood outlet port is connected to an arterial or venousreturn line, e.g. the arterial channel 486. During the period ofcerebral protection (when the arterial blood flow is reversed via theballoon(s) and/or clamp disclosed above), this initial setup permitsarterial blood to flow “passively” under natural arterial pressure,proximally through the sheath 24/224/324, through the sidearm 30/230/330and into the reservoir 598, without need for additional or externalpressure sources. Thus the arterial blood is collected passively in thereservoir apparatus 588; as the blood is collected in the reservoir 598air is vented through the air outlet port 596 (the valve 597 of which isleft open for this purpose).

After the period of cerebral protection is over and the naturaldirection of blood flow is restored (e.g., via deflation of theballoon(s) and/or release of the clamp), the collected blood can bereturned to the patient's vasculature, e.g. via the CCA 12 and implantedsheath 24/224/324. To do this the valves 591 and 597 are closed, and thevalve 590 is opened. The plunger 594 is then depressed to force thecollected blood out of the reservoir 598, through the filter 568 andvalve 590, and out through the blood outlet port 593. If a return linesuch as the arterial channel 486 is employed, the blood proceeds throughthe channel 486 and implanted sheath, and back into the CCA 12.

If desired a non-rigid overflow chamber (such as a ventilated bag) canbe connected to the air outlet port 596 to collect any blood thatoverflows the reservoir 598. As yet another option, a metering valve(not shown) can be installed on the sidearm 30/230/330 (or between thesidearm and the reservoir 598) to adjust the blood flow rate into thereservoir 598, to account for patient-to-patient variation in naturalarterial flow rates.

As a further option, a contrast reservoir (not shown) can be coupled tothe return line/arterial channel downstream of the blood outlet port593, via a “T” fitting or the like, to add contrast fluid as desired tothe blood as it returns to the patient.

Additional embodiments comprise kits. A first kit comprises theapparatus of FIG. 1; a second kit comprises the apparatus of FIGS. 2-2A;a third kit comprises the apparatus of FIGS. 3-3B; a fourth kitcomprises the apparatus of FIG. 4; a fifth kit comprises the apparatusof FIG. 4, with the apparatus of FIG. 4A substituted for thecorresponding apparatus of FIG. 4. A sixth kit comprises the apparatusof FIG. 4, with the apparatus of FIG. 5 substituted for thecorresponding apparatus of FIG. 4. Any of the aforementioned kits mayfurther comprise special short-length (e.g. 15-45 cm) guidewiresappropriate to the cervical approach. These short-length guidewires maybe constructed to be malleable and retain a bent shape imparted by theuser, in a manner similar to the malleable sheaths discussed above. Suchguidewires can be constructed from stainless steel or suitable softmetals, and can be made thicker than typical guidewires.

Instead of or in addition to these short-length guidewires, any of thekits mentioned above may comprise a “bent” introducer needle withappropriate angulation to decrease the likelihood of backwall arterialpuncture. The introducer needle may have a contrast injection sideport.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically-disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while a number of variations of the inventionshave been shown and described in varying levels of detail, othermodifications, which are within the scope of this invention, will bereadily apparent to those of skill in the art based upon thisdisclosure. It is also contemplated that various combinations orsubcombinations of the specific features and aspects of the embodimentsmay be made and still fall within the scope of the inventions.Accordingly, it should be understood that various features and aspectsof the disclosed embodiments can be combined with or substituted for oneanother in order to form varying modes of the disclosed inventions.Thus, it is intended that the scope of the present invention hereindisclosed should not be limited by the particular disclosed embodimentsdescribed above, but should be determined only by a fair reading of theclaims that follow.

What is claimed:
 1. A method of treating a carotid artery, comprising:forming an incision in the neck to expose the common carotid artery;forming an opening through a wall of the common carotid artery;positioning through the opening an arterial access sheath and dilatorsystem, wherein the arterial access sheath and dilator system comprisesan arterial access sheath and a dilator inside the arterial accesssheath, wherein the arterial access sheath comprises a first occlusionelement adapted to occlude the common carotid artery and wherein thedilator comprises a tapered distal end; removing the dilator from thearterial access sheath; and expanding the first occlusion element toocclude the common carotid artery.
 2. A method as in claim 1, whereinthe arterial access sheath includes a shunt that provides a pathway forblood to flow out of the arterial access sheath from the common carotidartery further comprising: connecting the shunt to a return site havinga lower pressure relative to the common carotid artery, the return sitebeing a venous return site or an external reservoir; reversing thedirection of natural blood flow in the common carotid artery; andshunting blood from the common carotid artery toward the return site viathe arterial access sheath and the shunt.
 3. A method as in claim 1,further comprising: introducing a therapeutic catheter through thearterial access sheath; and treating the carotid artery.
 4. A method asin claim 2, wherein the therapeutic catheter is a stent deliverycatheter and treating the carotid artery comprises deploying a stentusing the stent delivery catheter.
 5. A method as in claim 1, whereinthe arterial access sheath comprises a second occlusion element distalof the first occlusion element, and further comprising: positioning thesecond occlusion element in an external carotid artery branching fromthe common carotid artery; and expanding the second occlusion element toocclude the external carotid artery.
 6. A method as in claim 5, furthercomprising: introducing a therapeutic catheter into the carotid arterythrough an exit port located on the side of the arterial access sheathbetween the first and second occlusion elements; and treating thecarotid artery.
 7. A method as in claim 1, wherein the first occlusionelement is an inflatable balloon.
 8. A method as in claim 1, wherein thedilator comprises an internal lumen configured to receive a guidewire.9. A method as in claim 1, wherein positioning through the opening anarterial access sheath and dilator system comprises inserting thearterial access sheath and dilator system through the opening withoutpreviously inserting an introducer sheath through the puncture.
 10. Amethod as in claim 1, wherein positioning through the opening anarterial access sheath and dilator system comprises inserting thearterial access sheath through the opening without riding the sheathover a guidewire.
 11. A method as in claim 1, wherein the arterialaccess sheath includes a shunt that provides a pathway for blood to flowout of the arterial access sheath from the common carotid artery furthercomprising: connecting the shunt to an aspiration device; reversing thedirection of natural blood flow in the common carotid artery byactivating the aspiration device.